Process for flameproofing textile material

ABSTRACT

DESCRIBES A PROCESS FOR FLAMEPROOFING TEXTILES IN WHICH SUBSTANTIALLY ANHYDROUS ZINC CHLORIDE IN SUBSTANTIALLY ANHYDROUS SOLVENTS IS USED AS THE FLAMEPROOFING MATERIAL, THE SUBSTANTIALLY ANHYDROUS FLAMEPROOFING COMPOSITION PREVENTS CREASING AND SHRINKING OF THE TREATED TEXTILES.

United States Patent Olfice 3,687,720 Patented Aug. 29, 1972 3,687,720PROCESS FOR FLAMEPROOFING TEXTILE MATERIAL Werner Grunewalder, 89 AmFalder, 4 Dusseldorf-Holthausen, Germany No Drawing. Filed Nov. 26,1969, Ser. No. 880,377 Claims priority, application Germany, Dec. 6,1968, P 18 13 021.7 Int. Cl. C09d /18 US. Cl. 117-137 2 Claims ABSTRACTOF THE DISCLOSURE Describes a process for fiameproofing textiles inwhich substantially anhydrous zinc chloride in substantially anhydroussolvents is used as the fiameproofing material, the substantiallyanhydrous flameproofing composition prevents creasing and shrinking ofthe treated textiles.

The invention relates to a process for flameproofing textiles.

It is known to treat textile materials made of readily inflammablecellulose fibres with a fiameproofing treatment with aqueous solutionsor emulsions of various inorganic or organic compounds. In particular,already made up textiles, such as for example, curtains, protectiveclothing, special military textiles and the like are given suchtreatment. It has been found, however, that the known processes workingwith aqueous solutions or emulsions are not only complicated and timeconsuming, but also lead to damage of the cellulose textiles, sinceowing to the wet treatment, these tend to crease and shrink to aconsiderable extent.

An object of the present invention is to provide a flameproofing processfor cellulose textiles which will not materially crease or shrink thefabric.

Another object of the invention is to provide a process forflameproofing cellulose textiles which can be used in the cleaningmachines ordinarily used in chemical cleaning, and may be preceded withor followed with chemical cleaning or the cleaning may take placesimultaneously, in the same machine.

Another object is to provide a substantially anhydrous flameproofingconcentrate which when mixed with substantially anhydrous solvents usedin the preparation of the fiameproofing baths will give a substantiallyclear solution which will not tend to crease and shrink already made upcellulose textiles.

Various other objects and advantages of the invention will appear asthis description proceeds.

The present invention, therefore, provides an impregnating bath medium,for flameproofing cellulose textiles, comprising a mixture of asubstantially anhydrous zinc chloride in a lower alcohol, glycol orcarboxylic acid ester and an organic solvent utilizable for chemicalcleaning. The bath medium should be substantially anhydrous, having alow water content in the entire bath composition.

The process for flameproofing textiles which consist wholly orsubstantially of cellulose or regenerated cellulose fibres providedherein, comprises contacting said textiles with a bath medium comprisinga mixture of a concentrated substantially anhydrous solution of zincchloride in a lower alcohol, glycol or carboxylic acid ester and asubstantially anhydrous organic solvent utilizable for chemicalcleaning.

In order to prepare the impregnating baths, a concentrated stocksolution is first made by dissolving zinc chloride in an anhydrous loweralcohol or glycol containing 2 to 4 carbon atoms, such as ethanol,propanol, isopropanol, butanol, ethylene glycol, 1,3- or 1,3- propyleneglycols and the like. Further suitable solvents are esters of the saidalcohols with monocarboxylic acids which contain 1 to 4 carbon atoms, asfor example, ethyl acetate, the monoglycol ester of propionic acid andthe like. These concentrates contain 5 to 35% by weight of anhydrouszinc chloride, which may consist either of products of technical puritywith the lowest possible content of coloring or sludge-formingimpurities, or if desired products of high purity, for example,corresponding to the German harmacopoeia quality DAB 6.

10 to 60 g. per liter, calculated on anhydrous zinc chloride, of thesaid concentrates are added to the organic solvents to form animpregnating bath. The impregnating liquors consist of the solventsutilized in chemical cleaning, especially petroleum hydrocarbons ofboiling points of to 200 and halogenated hydrocarbons having 1 to 4carbon atoms such as methylene chloride, carbon tetrachloride,perchlorethylene, trifluorotrichloroethane, monofiuorotrichloromethane,etc.

These solvents should be largely water-free. It has surprisingly beenfound that the said concentrates containing zinc chloride can be mixedwith the solvents used for the preparation of impregnating baths givingclear or slightly turbid solutions. These baths are also sufficientlystable.

The process is eifected preferably in the cleaning machines used inchemical cleaning, suitably following a chemical cleaning. The textilesare treated with the impregnant medium at 2 0 to 35 C. for 2 to 10minutes and after centrifuging and drying are ready for use. Dependingon the amount of zinc chloride applied to the textile fibres, very goodflameproofing efiects can be at tained which correspond to the DINspecifications 53,906 and 53,907. In general, an application of 0.8 to8% by weight of zinc chloride, based on the weight of the fibre, isneeded.

In order to assist the effect, further known organic fiameproofingagents, provided they are soluble in the impregnating liquors, may beadded to the baths. For example, halogenated parafiins, especiallychlorinated paraflins, which simultaneously exert a specific softeningaction on the textile fibre, are suitable for this purpose. Theseingredients are added to the baths in amounts of from 3 to 20 g. perliter. Apart from these, further additions customary in textilefinishing may also be present, such as brightening agents, waterproofingagents, dressing agents or agents producing a high finish, for example,urea or melamine-formaldehyde condensation products and the like.

EXAMPLE 1 In a cleaning machine of the Biiwe R 9 M type, 6 kg. ofcurtains, consisting of rayon staple fibre rep, were cleaned as usualand then treated for 5 minutes in 60 liters of perchlorethylene with theaddition of 10 liters of butyl acetate in which 12% by weight ofanhydrous zinc chloride was dissolved. The textiles so treated, aftercentrifuging and drying in the cleaning machine, were difficultlyinflammable, in contrast to untreated curtains.

EXAMPLE 2 In the cleaning machine used in Example 1, 8 kg. of workingclothes, consisting of cotton twilled fabric, Were chemically cleanedand then flameproofed. The flameproofing was carried out by treating thefabric for 5 minutes in 60 liters of trichloroethylene with an additionof 12 liters of ethyl glycol, in which 15% of anhydrous zinc chloridewas dissolved. After centrifuging until the residual moisture was 80%,the suits were dried with hot air. The estimation of the flameproofingelfect was carried out, after air conditioning under standard conditionsaccording to the DIN specification 53,907. In comparison with untreatedgoods, the following values were obtained:

It can be seen from the values in the table that the treated cottontwill fabric is difficulty inflammable.

EXAMPLE 3 2 kg. of staple fibre gabardine were treated for minutes in 20liters of monofluorotrichloromethane with the addition of 3 liters ofisopropanol, in which 15% of anhydrous zinc chloride (DAB 6) and ofcoconut fatty acid polydiethanolamide were dissolved. The material wasthen centrifuged and dried as usual. The treated material in contrast tothe untreated goods, was only difiicultly inflammable and had a softhandle.

EXAMPLE 4 25 kg. of welders protective suits, consisting of cottonmaterial, were chemically cleaned as usual in a 35 kg. naphtha plant.The centrifuged textiles were treated in 200 liters of naphtha (boilingpoint 140200 C.) for 5 minutes with the addition of 24 liters ofisopropanol, in which of anhydrous zinc chloride and 5% of a chlorinatedparaifin with a chlorine content of about 70% were dissolved. Aftercentrifuging and drying, the treated suits were satisfactorilyflarneproof.

Having now particularly described the nature of the said invention andin what manner the same is to be performed, what I claim is:

1. A process for simultaneously flameproofing and cleaning textilesconsisting wholly or substantially of cellulose or regenerated cellulosefibers which consists essentially of immersing said textile in a bath ata temperature of from to 35 C. for from 2 to 10 minutes, said bathconsisting of (1) a solution consisting of from 5% to 35% by weight ofanhydrous zinc chloride in an anhydrous solvent selected from the groupconsisting of (a) lower alcohols selected from the group consisting ofethanol, propanol, isopropanol and butanol, (b) glycols selected fromthe group consisting of ethylene glycol, 1,2-propylene glycol and1,3-propylene glycol, and (c) carboxylic acid esters thereof with acarboxylic acid selected from the group consisting of acetic acid andpropionic acid, and (2) an organic solvent utilizable for chemicalcleaning selected from the group consisting of petroleum hydrocarbons ofboiling points of 80 C. to 200 C. and halogenated hydrocarbons having 1to 4 carbon atoms, said bath having a concentration of 10 to g. perliter of said anhydrous zinc chloride, removing said simultaneouslyfireproofed and cleaned textiles from said bath and drying saidtextiles.

2. A process as claimed in claim 1 in which the zinc chloride is insolution in butyl acetate.

References Cited UNITED STATES PATENTS 1,940,668 12/1933 Mohn 252-1722,053,007 9/1936 Parkhurst 252-172 X 1,261,736 4/1918 Ferguson 252-812,250,483 7/1941 Hopkinson 117-137 2,369,200 2/1945 Amberson 106-152,464,342 3/ 1949 Pollak et a1. 117-137 FOREIGN PATENTS 5,130 3/1905Great Britain 106-15 132,813 11/1920 Great Britain 106-15 545,514 5/1942Great Britain 106-15 OTHER REFERENCES Speel and Schwarz, TextileChemicals and Auxiliaries,

2nd ed., Reinhold, New York, 1957, pp. 134-135.

PHILIP E. ANDERSON, Primary Examiner D. A. JACKSON, Assistant ExaminerUS. Cl. X.R.

